


P.O.S - Side Effect of Tae's Medicine

by Barrytrain, Timegal25



Series: Persona One Shots [71]
Category: Persona 5, Persona Series
Genre: F/M
Language: English
Status: Completed
Published: 2017-09-25
Updated: 2017-09-25
Packaged: 2019-01-05 03:05:25
Rating: Mature
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 3,246
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/12181689
Author URL: https://archiveofourown.org/users/Barrytrain/pseuds/Barrytrain, https://archiveofourown.org/users/Timegal25/pseuds/Timegal25
Summary: A Persona One Shot featuring Ren Amamiya & Tae Takemi, both from Persona 5.A different approach on this. This is set during the 1st time you visit Tae at the clinic in Persona 5. However, it ends differently as the medicine she gives her guinea pig gives Ren a shocking side effect.





	P.O.S - Side Effect of Tae's Medicine

Ren Amamiya walked into the examination office at Tae Takemi’s clinic, his task to get a hold of the rumoured medicine. The doctor stood over him, leaning against the door.  
“... That ‘medicine’ huh...?” She questioned.  
She immediately locked the door, startling him. Her normal look turned into a glare.  
“So... Which conversation of mine did you eavesdrop on to hear that?” She asked.  
Ren was shocked, believing he could just act normal about all this.  
“It was obvious, actually.” She continued. “You call that hiding? Not that I care of course.”  
She looked away a little, her head moving down.  
“I was going to dispose of that medicine anyway.” She sighed. “I got a little too carried away with it. But tell me; why would a high schooler kid yourself be so interested in that medicine?”  
He panicked a little, remaining silent.  
“It’s very strange, indeed. You don’t seem to be very athletic, so...” She continued. “... What exactly are you up to?”  
“It’s for brainpower.” He replied.  
“Brainpower...?” She questioned, her eyes widening. “Oh, for your entrance exams?”  
Ren nodded, smiling a little.  
“So, you’re looking to improve your concentration and reduce fatigue?” She asked. “Hm, that’s not the best idea. But if that’s what you wanna do...”  
She unlocked the door, moving out of the way of it slowly.  
“Then good luck with that.” She smiled. “I have no obligation to help you with that. Why don’t you have an energy drink or something?”  
“I need that medicine.” He begged.  
Her look turned to one of annoyance, scratching her head.  
“The medicine is really expensive.” She explained. “And it’s not something a high schooler can get his hands on. It costs almost as much as a car. Got it? So how about you just go home?”  
“Can I work for it?” He asked.  
“What, like part-time help...?” She questioned.  
She thought to herself a little. Maybe it wouldn’t be such a bad idea, having a guinea pig to try her experimental medicines and tablets.  
“... Do you consider yourself someone with a good amount of stamina?” She asked.  
He was confused.  
“I admit I have been looking for a young person around your age to help me out.” She explained. “But I haven’t been able to find one, even putting an ad in the paper. Are you up to it?”  
“What would I be doing?” He asked.  
“Do you want to do it or not?” She asked back.  
Ren panicked a little. There was no way he could say to this, especially if it would help him in the Phantom Thieves business. He nodded in agreement.  
“Ok then.” She smiled. “You’ll be participating in clinical trials for my medicine.”  
‘What!? Wh-What does she mean?’ He thought in shock.  
“Hang on, I’ll be right back.” She smiled, walking to her cupboard of experimental medicines.  
She handed him a cup of red liquid that he looked down at it in confusion. Even he was sceptical about drinking this.  
“Here you go.” Tae smiled.  
He continued looking down, unsure about it.  
“... Worried about the side effects, huh? Well, you can relax.” She assured him. “Rest assured, my autopsy is guaranteed to find out exactly what part of it killed you.”  
‘What!? It’s gonna kill me?!’ He thought in horror.  
“What, aren’t you going to take it?” She questioned. “The exit’s right there if you want to leave.”  
‘If I don’t drink this, Tae Takemi probably won’t sell me her medicine...’ He thought.  
“Well? Go on.” She said.  
“Bottoms up.” He shrugged, drinking it all down in one gulp.  
She couldn’t believe this, her eyes widening in shock.  
“I can’t believe you actually drank it...” She gasped.  
‘Bitter, yet sour. It’s beyond description.’ He thought, feeling the aftertaste in his mouth. ‘... However, it’s nothing I can’t handle...’  
“Wow... Still doing ok, huh? Hm. Not bad, for a high schooler.” She complimented.  
She went to go speak some more as she suddenly saw Ren blink. He held his head, feeling all fuzzy in the mind and tingly in the body. He got off the chair, collapsing on the bed as he blacked out.  
“... Welp, game over, I guess.” She sighed.  
Those were the last words Ren had heard before completely passing out.

As he laid unconscious on the bed, Tae walked over towards him, looking down at him.  
‘I wonder what the medicine does.’ She thought.  
She watched him twitch a little, his twitching getting worse by every second. Tae watched curiously.  
“I was only joking that it would kill you.” She chuckled.  
Before her eyes though, she saw Ren’s chest suddenly extend out a little, confusing her.  
“Ren...?” She asked, moving her hand towards him.  
He shook more, his body figure changed slowly before her eyes.  
“What in the...?” She began to say before screaming suddenly.  
Ren’s body was changing into a more feminine figure as she stepped back.  
“Huh!?” She gasped more, losing her cool attitude once more.  
His eyes began to open a little as Tae could see that his chest now had medium sized breasts, his body shape more curvy. His eyes were a little pink as he sat up slowly, rubbing his head.  
“Y-Your body...” Tae shook.  
“My body?” Ren questioned, even his voice was more feminine. “What's wrong with it?”  
“It’s... Female.” Tae replied.  
Ren tilted his head, confused.  
“... You don’t feel off?” She asked.  
“Of course not.” He shook his head, blushing a little. “Do I look off?”  
“Look at yourself!” Tae said.  
Ren looked down at his chest, holding his breasts a little, looking at his body.  
“I... Look normal? Don’t I?” He asked confused.  
“I... I guess...” Tae replied.  
‘Does he not notice?’ She thought. ‘Or is his mind telling him he’s always been female?’  
“Have we finished my guinea pig session doctor?” He giggled.  
“Y... Yeah...” She replied.  
Ren stood up, shaking her hand.  
“Do we have that deal still?” He smiled.  
She looked over his body, blinking in confusion and shock.  
“O-Oh yes!” She replied suddenly. “Of course... Um... Ok, it’s my turn to make good on my part of the deal. I don’t want the general public to know about my original medicines. Understood?”  
“Of course!” He cheered. “Thank you so much! Um... I'll see you next time!”  
He picked up his bag, walking out of the clinic. Tae watched his new butt sway a little as she blushed a little. As the door shut on its own, Tae immediately screamed in horror.  
“W-What just happened!?” Her eyes widened.  
She looked at the empty cup on her desk, her hands shaking.  
“I... I... I'm gonna get in trouble for this...” She gulped, before gasping again. “I-I can’t have anyone seeing him like this!”  
She ran out of the office after him. She looked about the alleyway of Yongen-Jaya for him. There in the distance, she saw him walking down the alleyway, humming softly.  
“H-Hey, wait!” She called out to him.  
He turned around curiously, seeing Tae run up behind him.  
“O-Oh Tae.” He blushed a little. “Wh-What's up?”  
“H-How about... You stay the night at my place...?” She offered.  
“Wh-Why?” Ren asked.  
“U-Um... We can get to know each other more...?” She smiled softly. “After all, don’t you want more medicine?”  
“Sure! I should go back and tell Sojiro though because...” He said before being cut off.  
“No!” She panicked. “... I’ll tell him. He needs some convincing.”  
“O-Oh... O-Okay then.” He said confused.  
“Just walk through the office to the back and you'll see the stairway up to my place.” She instructed. “I’ll meet you there.”  
“... Alright then.” Ren said nervously, walking slowly back to the clinic.  
Tae sighed in relief.  
“Thank god that worked.” She looked down. “Now to get Sojiro to convince him it’s a good idea. Especially him... He can’t find out.”

Time passed as Ren and Tae sat on the couch upstairs from the clinic where Tae called home. He slipped off his shoes, looking down at his clothes.  
“Even though it’s a school uniform, I should really get myself some new clothes.” He sighed softly, texting on his phone.  
“Y-Yeah.” Tae said nervously. “Um... Who you texting?”  
“Just a friend about schoolwork.” He replied.  
Unknown to her however, Ren had been texting Ryuji about Phantom Thieves related stuff. She tried to peek to see whom he was texting. But, he put his phone in his pocket smiling.  
“Ah, ah, ah... No peeking.” He giggled.  
“S-Sorry...” She apologised.  
“It’s okay!” He cheered.  
They were both silent, looking at each other. Tae looked over Ren, his new body making her feel some unusual feelings for someone who was just a guinea pig to her.  
“So, what other kinds of medicine will I be trying later on down the line?” He tried to start up a conversation.  
“I’m not sure...” Tae replied.  
“To be honest, when I first drank that medicine and passed out, you seemed terrified. And then you question my body... A-And you don't seem like yourself ever since.” Ren explained.  
“I’m sorry.” Tae scratched the back of her head. “I mean, we just met after all... So I was surprised.”  
“Don't be. Just continue to be that cool, chilled punk girl I first saw when I entered the clinic. Or was that an act?” He giggled.  
“You’re right.” She smiled, chuckling a little.  
“Aren’t I still your little guinea pig?” He teased.  
“You are.” She replied, making him blush. “Hungry?”  
“Y-Yes please!” He nodded, smiling.  
She stood up and walked into her kitchen, heading to the fridge. She opened it, seeing food and drink, a shelf dedicated to experimental medicine wrapped up in cling film, in either pots or cups.  
‘Maybe I should try one of these pills to cure him.’ She thought to herself. ‘I’ll be in some deep water if he’s still like this by the morning.’  
She grabbed some snacks, taking a small pill with her before closing the fridge. She walked back into the living room, sitting next to him. She handed him a pill first.  
“Here, take this.” Tae ordered. “We might as well do another test.”  
He took it into his hand, inspecting it. It looked just like a normal pill to him.  
“What’s this one going to do?” He asked. “Nothing again?”  
“I’m... Not sure.” She replied.  
‘I guess he really doesn’t know what happened.’ She concluded in her mind. ‘I thought it would be that he was so dense... But I guess not.’  
Ren took the pill, swallowing it. Tae only watched him, waiting. He only blinked a few times, blushing a little.  
“You... Don’t have a crush on me... R-Right?” He questioned.  
“Nope, not yet anyways.” She smiled a little. “Why do you ask?”  
“I...” He began to reply, suddenly holding his head. “I... My mind feels fuzzy...”  
Tae gasped, her eyes widening. Right before her eyes, he collapsed against her, his face resting against her chest as she blushed badly.  
“I guess, another game over.” She sighed. “Hopefully this’ll do something.”

A few minutes passed as Ren looked up at Tae looking down at him. It didn’t take him long to realise where his face was, moving it away quick. Tae looked over him. Nothing had changed to her disappointment.  
“H-Hey! I'm sorry!” He apologised.  
“How... Do you feel?” She asked.  
“I... Feel like I want to do something... Weird.” He replied. “Is that bad?”  
“Weird? Like what?” She questioned.  
“Well... I-I don’t want to say it.” He replied nervously.  
“Go on.” She smiled. “I need to know what that medicine did to you.”  
He smiled, looking down at her feet.  
“Can I... Do you want me to paint your toenails?” He asked.  
“... S-Sure...” She nodded, looking at him confused.  
He jumped up from his seat, heading into Tae’s bedroom to search for some nail polish. She started to shake, things had gotten worse.  
“O-Oh no.” She gulped. “I think that made it worse.”  
She tried to think what else could be done, though her trail of thought was halted as Ren came back in, holding a bottle of red nail polish in his hand. He knelt down, taking her left foot in his hand as he painted her toenails red smiling. Unusual for Tae, she was actually enjoying this. She watched him silently, feeling herself sweat a little from failing to return Ren to normal.  
“You're really not being yourself Ma'am. Smile for your guinea pig.” He teased, taking her right foot and painting her toenails red also. “Tell her what a good jobs she's doing.”  
He rubbed his fingers against her soles as he continued to paint.  
“You’re a good girl.” She smiled, playing along.  
He blushed, giggling to himself as he finished up painting her toenails, giving them a gentle blow. She looked at her toenails. They were spot on, though her mind was still telling her that she desperately need to try and change Ren back.  
“There we are. So perfect.” He complimented.  
“I... Thank you.” She smiled, moving her feet away from him. “Listen, how about we do another test.”  
“Really?” He gasped. “A-Alright.”  
She stood up, holding his hands to make him stand up too.  
“To the kitchen please.” She requested.  
He nodded, giggling as they both walked up to the fridge. This time however, Tae took out a medicine cup of purple liquid, handing it to him.  
“Here, drink this.” She asked.  
He nodded, drinking it all in one, swallowing. Tae watched as the effects became apparent immediately. He began to twitch as his eyes immediately widened.  
“... Ren?” She asked, moving her hand towards him.  
Before her eyes, he started to drool uncontrollably, his expression being a mindless smile. She pushed on his forehead, waiting for the result. Like a punching dummy, he moved back a little before moving back up, wobbling back and forth a little.  
“Stiff as a board it seems...” She said. “Can you hear me?”  
He blinked a little, replying with a yes.  
“Um... Can you move? Walk around.” She requested.  
He began to walk around slowly in the kitchen, his movements stiff.  
“Stop.” She said, watching him stop immediately in front of her.  
She looked over him, moving her hands towards him. She was curious to see how he felt, his figure being the way it was now. His body was so feminine, soft and smooth.  
“Oh my.” She gasped. “Your body is so...”  
She looked at his breasts, down to his feet. His breasts were slightly bigger than hers, his feet arched as he only stared at her, drooling. She looked back up, screaming a little.  
“Oh no!” She gasped. “It’s even worse.”  
She ran up to the fridge, moving her hand to open it before stopping herself. After three kinds of medicine, she was hesitant to even try another medicine that may or may not make things worse.  
‘No... I must do what it takes.’ She thought.  
She opened the fridge; nervously grabbing one that looked similar to the first medicine she made him try, though it was a pink colour.  
“Here, open wide and swallow.” She ordered.  
He opened his mouth slowly as she poured it in, hearing him swallow. He blinked, looking at her.  
“... Nothing huh?” She sighed. “I guess...”  
She was cut off as Ren, crouched down, holding onto his stomach. He groaned before shaking violently and collapsing on the kitchen floor.  
“Ren!?” She panicked, shaking him a little. “Wake up!”  
However, he wasn’t moving at all.  
“Oh no!” She cried out.  
She carried him downstairs, back into her office and laid him down on the bed. She began to sweat, shaking him a little.  
“No, no!” She panicked more. “Wake up!”  
Suddenly, she saw that Ren’s chest was slowly decreasing in size, his movements returning.  
“O... Oh thank god...” She sighed in relief.  
He twitched once more, his body slowly returning to its original form. She sat down, breathing in slowly.  
‘O-Okay... Got to play this cool. Like nothing had happened.’ She thought to herself.  
She maintained her cool, watching him wake up, slowly sitting up.  
“You’re alright.” Tae smiled weakly.  
Ren rubbed his head, his memory seemingly forgotten what had happened the past half day.  
“What... Happened?” He questioned.  
“You... Passed out.” She explained. “You don’t recall anything?”  
He shook his head.  
“My body hurts a little... What was that medicine you gave me?” He asked, groaning a little.  
“It... Must have been a sleeping pill.” She fibbed.  
“I see...” He looked down, checking the time on his phone. “Gah! I-I should be at Leblanc!”  
“Head home.” Tae smiled. “... But, come back tomorrow alright?”  
“Sure!” He nodded. “For more trials?”  
“Yes.” She nodded. “If you still want the medicine.”  
“I do.” Ren nodded, standing up.  
“Good, see you tomorrow.” She said.  
She let him out of the clinic, watching him run down the alleyway back to Leblanc. The day played out in her head, making her go dark red.  
I... I’m very... Aroused.” She bit her lip. “I wonder...”  
She thought about all the medicine she gave Ren today, already coming up with new ideas on new treatments.  
‘So many ways to play with them...’ She thought to herself. ‘Need to look into a way to make them... Bigger.’  
She headed back into her office, working all night on her medicines, smiling to herself.  
‘Maybe today... Wasn’t so bad after all.’ She thought, grinning cheekily.

The next evening came and as she said, Ren visited her at the clinic once more. She had him try out some enhanced medicine from yesterday. They were both upstairs in Tae’s apartment as she was laid on the couch with her feet up, wiggling her toes a little. Below her was a small medicine cup of purple liquid that she had planned to give to Ren. She watched, her eyes directed towards the kitchen as a feminine Ren stood, pouring some wine in a glass for her. He was only wearing a black apron, walking towards her with the glass of wine in his hand.  
“Here you are Tae.” He smiled, handing her the glass.  
She took it off him, thanking him before she handed him the small medicine cup.  
“Take this.” She grinned cheekily. “Guinea pig.”  
Ren chuckles as he drank it, licking his lips a little. It was rather sweet, never before had he enjoyed the taste of medicine. Tae’s eyes focused on his chest as she watched them grow a little larger.  
‘It worked...’ She blushed.  
He blushed, sitting next to her and putting her feet on his lap as he giggled.  
“I’m enjoying this.” He smiled.  
“Oh, you have no idea how much you’re helping me with my work.” She giggled.  
Tae could only feel aroused at the sight she saw in front of her. A young man whom she could use not just as a test subject but also as someone she could perfect to her image. She could change his gender and body features at will, and that made her more than happy.  
“If you’re a good girl, you’ll give me the truth about why you want my special medications.” She teased.  
“I thought you didn’t care.” Ren said.  
“Let’s say I changed my mind.” She bit her lip, looking at his body. “I’ve taken an extreme liking to you.”  
“So you do have a crush on me?” He questioned.  
“Indeed.” She replied. “And you’ve got a crush on me.”  
Ren blushed, nodding as Tae chuckled.  
“This is going to fun.” She smiled.


End file.
